Calorie Deficit Calculator
Based on your TDEE & target fat loss pace
Best muscle retention
Recommended
Monitor energy
Short term only
How To Calculate Your Calorie Deficit
A calorie deficit occurs when you consume fewer calories than your body burns in a day. Your body then turns to stored fat as a secondary fuel source, which is how fat loss happens. The size of your deficit determines how fast you lose fat, and getting this number right is the difference between sustainable progress and burning out after two weeks.
The starting point is always your TDEE (Total Daily Energy Expenditure), the total calories you burn in a day. From there, you subtract your chosen deficit to get your daily calorie target.
How Much Should Your Deficit Be?
| Pace | Daily Deficit | Weekly Loss | Best For |
|---|---|---|---|
| Slow | -250 kcal | ~0.25 kg | Athletes, muscle retention priority |
| Moderate | -500 kcal | ~0.5 kg | Most people, sustainable and effective |
| Fast | -750 kcal | ~0.75 kg | Higher starting body fat, short phases |
| Aggressive | -1000 kcal | ~1 kg | Short-term only, with close monitoring |
Why Protein Is Critical In A Deficit
When you're in a calorie deficit, your body can break down muscle tissue for energy if protein intake is too low. Keeping protein high, at least 1.6-2.2g per kg of bodyweight, signals to your body to preserve muscle while burning fat instead. This is why the macro split at a deficit is heavily weighted toward protein compared to a maintenance or bulk phase.
The Minimum Calorie Floor
There's a lower limit to how far you should take your deficit. Going below 1,200 kcal/day for women or 1,500 kcal/day for men typically results in muscle loss, hormonal disruption, fatigue, and a slowed metabolism. If your calculated target falls below these thresholds, the right move is to increase your activity level rather than cut calories further.
What To Do When Fat Loss Stalls
Fat loss rarely moves in a straight line. After 4-6 weeks at the same deficit, your body adapts, your TDEE decreases as you lose weight. When this happens, recalculate your TDEE at your new bodyweight and adjust your target. Don't cut calories further, instead, recalibrate from your updated maintenance figure.
